1. Field of the Invention
The invention relates to a vehicle driving apparatus used for vehicles such as automobiles and so forth.
2. Description of the Related Art
As a driving source for a vehicle, vehicle driving apparatuses including an engine and an electric motor are known. For example, such a vehicle driving apparatus is disclosed in U.S. patent application Publication No. 2003/0127262 A1. The vehicle driving apparatus disclosed in this publication includes an engine and first and second electric motors. A flange of a rotor of the first electric motor is directly connected to a crankshaft of the engine with bolts. Furthermore, a damper is disposed on the opposite side of the engine with respect to the flange of the rotor. Moreover, a clutch and the second electric motor are disposed on the opposite side of the engine with respect to the damper. Thus, the engine, the first electric motor, the damper, the clutch, and the second electric motor, form a single unit.
When assembling the thus configured vehicle drive apparatus, the rotor is directly mounted to the crankshaft of the engine before covering the rotor with a housing, a cover, or the like. This may lead to a problem that foreign matter such as iron powder and so forth adheres to a magnetized portion of the rotor, for example. Furthermore, the rotor is connected to the crankshaft of the engine, and thus the position of the rotor is fixed. On the other hand, a stator is fixed on the housing, and thus the position thereof is fixed. Such a configuration leads to a positional error between a rotor axis and a stator axis due to a positional error of the crankshaft of the engine and the housing. In some cases, this leads to difficulty in aligning the rotor axis with the stator axis with high precision.
To counter this, for example, the rotor of the first electric motor may possibly be supported by a support wall fixed on the housing. Adding such a support wall, however, may result in a greater axial length of the vehicle driving apparatus, which is not desirable.